Asphalt emulsions, products made from asphalt emulsions, and processes for making fibrous mats from asphalt emulsions

ABSTRACT

The invention relates to asphalt emulsions comprising an asphalt component selected from the group consisting of a solvent extracted asphalt, an oxidized asphalt, and combinations thereof. The invention also relates to products made therefrom, including fibrous mats comprising a fiber component, such as glass fibers, and a binder component comprising an asphalt emulsion. The invention further relates to wet-laid processes for manufacturing fibrous mats and that employ the use of an amphoteric surfactant, which is applied to a wet fiber web prepared from a dispersion of fiber components, such as glass fibers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 12/625,935 filed Nov. 25, 2009, which claims the benefit of U.S.Provisional Application No. 61/117,734, filed Nov. 25, 2008; U.S.Provisional Application No. 61/117,735, filed Nov. 25, 2008; U.S.Provisional Application No. 61/117,739, filed Nov. 25, 2008; U.S.Provisional Application No. 61/117,742, filed Nov. 25, 2008; and U.S.Provisional Application No. 61/118,044, filed Nov. 26, 2008, all ofwhich are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to asphalt emulsions, products made from asphaltemulsions, in particular to fibrous mats useful for making buildingmaterials, and processes for manufacturing the fibrous mats. The fibrousmats made with the asphalt emulsions of the invention allow for thepreparation of lighter than traditional fibrous mats while providingexcellent tear resistance and tensile strength.

2. Description of the Prior Art

High strength, uniform thin sheets of glass fibers are important in thebuilding materials industry. These products are typically used inroofing shingles.

In the past, asphalt roofing shingles have been constructed of anorganic rag felt impregnated and coated with asphalt or other bituminoussubstance. However, asphalt-impregnated rag felt mats are difficult tomanufacture in large quantities and are costly.

Glass fiber mats were developed in an attempt to improve upon themore-expensive and difficult to process asphalt-impregnated rag feltmats. There are numerous glass mats described in the art that are formedcommercially of glass fibers. These mats include glass fibers heldtogether by binder materials. A common binder material used in glassmats is urea-formaldehyde, which may be deemed undesirable if toxicformaldehyde is released from the mats, when they are stored.

Efforts have been made to improve glass mat strength. These efforts havefocused on modifying the binders used in making fiber mats, theprocesses employed in manufacturing the glass mats and/or the fibrouscomposition of the mats.

U.S. Pat. No. 2,731,066 describes a glass fiber mat formed from a dryprocess. The mat includes chopped glass fibers arranged in a haphazardpattern reinforced with continuous strands, yarns or slivers boundtogether with a bonding agent. Suitable bonding agents disclosed in U.S.Pat. No. 2,731,066 include asphaltic compounds, coal tar products,pitch, phenol formaldehyde resins, rubber, starch, sugar, gelatin,polystyrene, methyl methacrylate or like products.

U.S. Pat. No. 4,135,029 discloses a wet-laid process for making glassfiber mats which have improved tear strength over glass mats made by thedry process. The mats include at least some randomly oriented choppedglass fibers and fiberglass strands, yarns or slivers embedded inseparate layers therein. U.S. Pat. No. 4,135,029 states that commonlyknown bonding agents may be used to bond the fibers together, such asurea resins, phenolic resins, bone glue, polyvinyl alcohol, polyvinylacetates and various compound and stabilizing reagents.

U.S. Pat. No. 4,178,203 relates to the manufacture of glass fiber matproducts made by the wet-laid process wherein the wet fibrous web istreated with an anionic surfactant at any time after the web is preparedand before binder is applied to the mat. The resultant mat is said tohave increased wet-strength.

U.S. Pat. No. 4,178,204 relates to the manufacture of glass fiber matproducts made by the wet-laid process wherein a wet fibrous web isprepared that is treated with an anionic polyelectrolyte prior to binderbeing applied to the mat. The anionic polyelectrolytes are eithersoluble in water or can provide soluble dispersible salts in water, suchas with an alkali metal hydroxide, ammonia or a low molecular weightorganic amine. The resultant mat is said to have increased wet-strength.

U.S. Pat. No. 4,178,206 relates to the manufacture of glass fiber matproducts made by the wet-laid process wherein glass fiber dispersionsare prepared by mixing chopped glass fibers in water with a small amountof a select group of cationic quaternary ammonium compounds which haveat least two long chain groups as part of the molecule. The resultantdispersions are said to have a relatively high glass fiber consistency.

U.S. Pat. No. 4,179,331 relates to the manufacture of glass fiber matproducts made by the wet-laid process wherein glass fiber dispersionsare prepared by mixing chopped glass fibers in water with a small amountof an amine oxide surfactant. The resultant dispersions are said to havea relatively high glass fiber consistency.

U.S. Pat. No. 5,407,536 relates to the manufacture of glass fiber matproducts made by the wet-laid process wherein glass fiber compositionsare prepared by mixing chopped glass fiber bundles in water with a smallamount of an alkylamidoalkyl sultaine surfactant, which is amphoteric,to disperse the bundles into individual fibers prior to preparing thewet fibrous web. The resultant dispersions are said to have a relativelyhigh glass fiber consistency.

U.S. Pat. No. 2,701,777 discloses asphaltic emulsions and glass matsmade from the asphaltic emulsions. The asphaltic emulsions are used inthe preparation of glass fiber mats. The asphaltic emulsions are madewith an anionic component in the form of a fatty acid ester or mixedfatty acid esters of polyethylene glycol, the palmitic acid ester ofdiethylene glycol and the oleic acid ester of triethylene glycol, castoroil fatty acids of triethylene glycol and palm oil fatty acid esters ofdiethylene glycol.

U.S. Pat. No. 4,233,353 discloses glass fiber mats constructed from twofibrous components, including individual filaments, which provide auniform denseness for impregnation of saturant asphalt to the mat afterits formation, and extended fiber elements formed by longitudinalextension and connection of fibers from bundles of glass fibers in awet-laid process, which furnish tear resistance. The glass fibers arebonded together with any commercially available binder, such asurea-formaldehyde or phenol-formaldehyde resins.

U.S. Pat. No. 5,744,229 discloses a glass fiber mat that contains from68% to 90% glass fibers and from 10% to 32% binder. The binder containsfrom 2% to 90% polymer modified asphalt and from 10% to 98%thermosetting resin by weight of the binder. The preferred asphalt is ACgrades of asphalt because they are soft and easily emulsified. The tearstrength of the disclosed glass fiber mats, as shown in Table 1 of U.S.Pat. No. 5,744,229, was better than a control glass fiber mat made witha conventional binder containing SBR polymer and urea formaldehyderesin, although the tensile strength was not as good as the control.

U.S. Pat. No. 6,817,152 discloses a glass fiber mat having improved tearresistance that includes randomly oriented glass fibers, a polysiloxanecompound and a formaldehyde-type binder containing a binder modifierwhich is a crosslinked styrene/acrylic polymer.

It is an object of the present invention to provide new and improvedasphalt emulsions which allow for the economic manufacture of productsmade from asphalt emulsions, such as fibrous mats. It is also an objectof the present invention to provide fibrous mats that are made withasphalt emulsions which allow for the preparation of fibrous mats thatare strong, light weight and possess excellent tear resistance andtensile strength. It is a further object of the present invention toprovide new and improved processes for manufacturing wet fibrous webswhich have improved wet-strength. The processes are useful for preparingfibrous mats, such as the fiber mats of the present invention. Theprocesses of the present invention employ an amphoteric surfactant whichis applied to the wet-laid fiber web prior to the application of binder.

SUMMARY OF THE INVENTION

In accordance with the invention, new and improved asphalt emulsions areprovided for the economic manufacture of products made from asphaltemulsions, such as products used in the building industry and as acoating material. In particular, the invention provides for fibrous matsand roofing materials that are made from asphalt emulsions and that haveexcellent tear resistance and tensile strength. The invention furtherprovides for cost effective processes of manufacturing fibrous mats,which may be lighter in weight than conventional fibrous mats used inthe building industry.

The asphalt emulsion may include combinations of the following: anasphalt component, a dispersant, a thixotropic agent, a surfactant, acatalyst, an aromatic oil, a resin, a cross-linking agent, aplasticizer, a wax, and a polymer. In one embodiment, the asphaltcomponent is selected from the group consisting of solvent extractedasphalts, oxidized asphalts and combinations thereof.

In a preferred embodiment of the invention, the asphalt emulsionconsists essentially of an asphalt component, a dispersant, athixotropic agent, a surfactant, a catalyst, an aromatic oil, andoptionally, a polymer. In another preferred embodiment of the invention,the asphalt emulsion consists essentially of an asphalt component, adispersant, a thixotropic agent, a resin, and optionally, a polymer. Inyet another preferred embodiment of the invention, the asphalt emulsionconsists essentially of an asphalt component, a dispersant, athixotropic agent, a surfactant, a catalyst, a resin, and optionally, apolymer. In a further preferred embodiment of the invention, the asphaltemulsion consists essentially of an asphalt component, a surfactant, acatalyst, a resin, a cross-linking agent, a plasticizer, a wax, andoptionally, a polymer.

In an embodiment of the invention, the asphalt emulsion may also includeany bituminous material, such as tars, pitches or asphalts, includingasphalts that are natural or petroleum derived.

In a particularly preferred embodiment, the solvent extracted asphalt ofthe invention is propane deasphalted asphalt (PDA). Preferred oxidizedasphalts include Type I, Type II, Type III and Type IV asphalts.

The present invention further relates to building materials, such asroofing shingles, gypsum boards and underlayment made with fibrous mats,and coating materials used, for example, for athletic surfaces,playgrounds, coatings on roofs and the like. Fibrous mats of the presentinvention comprise a fiber component and a binder component. Suitablefiber components include glass fibers, preferably prepared by a wet-laidprocess. Preferably, the glass fibers are from about 1.0″ to about 1⅜″in length. An exemplary binder component comprises asphalt emulsions ofthe present invention. The asphalt emulsion binds together randomlyoriented glass fibers made by a wet laid process to form a glass fibermat having excellent tear resistance and tensile strength.

The processes of the invention relate to wet-laid processes formanufacturing fibrous mats and employ the use of an amphotericsurfactant, which is applied to a wet fiber web prepared from adispersion of fiber components. Suitable fiber components includerandomly oriented glass fibers preferably prepared by a wet-laidprocess. Preferably, the glass fibers are from about 1.0″ to about 1⅜″in length. The amphoteric surfactant may be applied to the wet fiber webby any means known in the art. In a preferred embodiment, the amphotericsolution is a dilute solution which is applied to the wet fiber webafter the web is prepared but before the binder component is applied.

In a preferred embodiment, the processes of the invention comprisetreating a wet fiber web with an amphoteric surfactant. The wet fiberweb may be prepared by combining chopped glass fibers, water, adispersant and a viscosity modifier in a head box to form a dispersionof glass fibers. The dispersion of glass fibers may then be applied to aconveyor in the presence of a vacuum to form a wet fiber web. After theamphoteric surfactant is applied to the wet fiber web, a bindercomponent may then be applied, preferably simultaneously with theapplication of a vacuum. An exemplary binder component comprises asphaltemulsions of the present invention. Once the binder is applied, the wetfiber web may be dried in an oven and then may further be exposed toinfrared rays. The binder may be heated to 165° F. to allow betteradhesion of the materials to the glass fibers before curing.

BRIEF DESCRIPTION OF THE DRAWING

For a better understanding of the present invention, reference is madeto the following drawing. Referring to the Drawing:

FIG. 1 shows a schematic representation of an exemplary process inaccordance with the invention.

DETAILED DESCRIPTION

Asphalt Emulsions

In the present invention, asphalt emulsions for use, e.g., in buildingmaterials are provided. The asphalt emulsions are particularly usefulfor the preparation of fibrous mats that may be employed in buildingmaterials, such as roofing shingles, gypsum boards and underlayment. Theasphalt emulsion comprises an asphalt component. In a preferredembodiment, the asphalt component is selected from the group consistingof solvent extracted asphalt, oxidized asphalt, and combinationsthereof. The asphalt emulsion may further comprise a bituminous materialsuch as tars, pitches or asphalts, including asphalts that are naturalor petroleum derived. In one embodiment, the petroleum derived asphaltis paving grade asphalt such as asphalt cement (AC), including AC-2.5,AC-5, AC-10, AC-20, AC-30 and AC-40.

In a preferred embodiment, the asphalt component is solvent extractedasphalt. Solvent extraction techniques are well-known in the art forpreparing solvent extracted asphalt compositions. These techniquestypically employ alkanes, such as propane, as the solvent and arecommonly referred to as deasphalting techniques. The asphaltcompositions obtained by deasphalting techniques may be referred to aspropane extracted asphalt (PEA), propane washed asphalt (PWA), orpropane deasphalted asphalt (PDA). The solvent extracted asphaltcompositions are obtained from treating a normal crude oil and/orresidue feedstock with an alkane, such as propane, to obtain a treatedasphalt in which the general level of saturates, compared to theoriginally treated material, is decreased, and the amount of asphaltenesis generally increased. In a preferred embodiment, the solvent extractedasphalts of the invention contain asphaltenes generally in the amount ofabout 25% to about 35% by weight and more typically from about 30% toabout 35% by weight. The solvent extracted asphalt compositions may bemade with bituminous material, such as tars, pitches or asphalts. Thesolvent extracted asphalt compositions are relatively inexpensivebecause they are the residue of processes for obtaining the higher valueoil portions from the petroleum source. The solvent extracted asphaltsare typically very hard and not easily manageable.

In another preferred embodiment, the asphalt component includes oxidizedasphalt, also known as an air blown asphalt. Any oxidized asphalt may beused in accordance with the invention. In a preferred embodiment, theoxidized asphalt is selected from the group consisting of Type I, TypeII, Type III and Type IV. More preferably the oxidized asphalt isselected from the group consisting of Type II, Type III and Type IV. Ina particularly preferred embodiment, the oxidized asphalt is Type IV.

The asphalt emulsion of the present invention may further include adispersant, and/or a thixotropic agent, and/or a surfactant, and/or acatalyst, and/or an aromatic oil, and/or a resin, and/or a cross-linkingagent, and/or a plasticizer, and/or a wax, and/or a polymer and/orcombinations thereof. The dispersant may be any dispersant known in theart, such as an epoxy resin dispersant. For example, the dispersant maybe Erisys® GA240, which is available from CVC Specialty Chemicals, Inc.(Moorestown, N.J.). Erisys® GA240 is 100% of a glycidyl ether ofmeta-xylenediamine.

The thixotropic agent may be any thixotropic agent known in the art,such as carboxy methylcellulose (CMC), which is available from severalcompanies, including Hercules Chemical (Jiangmen) Co., Ltd. (GuangdongProvince, China).

The surfactant may be any surfactant known in the art, such as Redicote®E-11, Redicote® AP and Redicote® C-450, all of which are available fromAkzo Nobel (Amsterdam, Netherlands); Stepanol 250A and combinationsthereof Redicote® E-11 is a cationic surfactant containing 50%quaternary ammonium salt, 35% isopropanol and 15% water (by weight).Redicote® AP contains 62.5% alkoxylated fatty polyamines, 33.5%solvent(s) and 8% fatty acids (by weight). Redicote® C-450 is a cationicsurfactant containing 100% fatty amine by weight. Stepanol 250A,available from Stepan Company (Northfield, Ill.), is an anionicsurfactant. Stepanol 250A also includes a resin, a cross-linking agentand a plasticizer and, therefore, may also be used in the presentinvention for any of those purposes or a combination thereof.

The catalyst may be any catalyst known in the art, such as UP 1935,hydrochloric acid (HCl) and combinations thereof UP 1935 is a vulcanizerdispersion available from Ultrapave® Corporation (Dalton, Ga.).

The aromatic oil may be any aromatic oil known in the art, for example,kerosene, heavy lube oil, diesel fuel or combinations thereof Thepresence of the aromatic oil decreases the viscosity of the asphaltemulsion and also makes the emulsion more stable. It is believed thatthe kerosene provides bonding, attraction, low viscosity, easypenetration between joints and increase tensile value. It is furtherbelieved that heavy lube oil, such as motor oil, provides flexibility tothe fibrous mats of the invention. Diesel fuel comprises kerosene andheavy lube oil.

The resin may be any resin known in the art, such as urea formaldehyde,Sylvatac® RE 100, Stepanol 250A and combinations thereof. Sylvatac® RE100 is 100% of a pentaerythritol ester of rosin, which is available fromArizona Chemical (Jacksonville, Fla.).

The cross-linking agent may be any cross-linking agent known in the art,such as castor oil, Stepanol 250A and combinations thereof Castor oil isavailable from several companies, including Cargill, Incorporated(Minneapolis, Minn.).

The wax may be any wax known in the art, including waxes made frompolyethylene such as CWP561, waxes made from petroleum such as CWP461,waxes made from coal such as H6 and waxes made from natural gas such asC105, all of which are available from Chusei, (USA) Inc. (Pasadena,Tex.).

The polymer may be any polymer known in the art, such as styrenebutadiene (SBR), including Rovene® 4040. Rovene® 4040 is a nonionicemulsion of carboxy modified styrene butadiene polymer available fromMallard Creek Polymers, Inc. (Charlotte, N.C.).

In a preferred embodiment of the invention, the asphalt emulsion mayinclude combinations of the following: from about 1.0% to about 50%,more preferably from about 5% to about 25%, asphalt component; fromabout 0.01% to about 1.0%, more preferably from about 0.1% to about0.5%, dispersant; from about 0.01% to about 1.0%, more preferably fromabout 0.1% to about 0.5%, thixotropic agent; from about 0.01% to about2.0%, more preferably from about 0.1% to about 1.0%, surfactant; fromabout 0.01% to about 2.0%, more preferably from about 0.1% to about1.0%, catalyst; from about 0.01% to about 1.0%, more preferably fromabout 0.1% to about 0.5%, aromatic oil; from about 0% to about 50%, morepreferably from about 0.1% to about 25%, resin; from about 0.01% toabout 1.0%, more preferably from about 0.1 to about 0.5%, cross-linkingagent; from about 0.01% to about 1.5%, more preferably from about 0.1%to about 0.75%, plasticizer; from about 0.01% to about 1.5%, morepreferably from about 0.1% to about 0.75, wax; from about 0% to about5%, more preferably from about 0.1% to about 1.5%, polymer orcombinations thereof.

In an additional preferred embodiment of the invention, the asphaltemulsion consists essentially of an asphalt component, a dispersant, athixotropic agent, a surfactant, a catalyst, an aromatic oil, andoptionally, a polymer. In a preferred embodiment, the asphalt emulsionconsists essentially of from about 5% to about 50%, more preferably fromabout 10% to about 30%, asphalt component; from about 0.01% to about1.0%, more preferably from about 0.1% to about 0.5%, dispersant; fromabout 0.01% to about 1.0%, more preferably from about 0.1% to about0.5%, thixotropic agent; from about 0.01% to about 1.0%, more preferablyfrom about 0.1% to about 0.5%, surfactant; from about 0.01% to about2.0%, more preferably from about 0.1% to about 1.0%, catalyst; and fromabout 0.01% to about 1.0%, more preferably from about 0.1% to about0.5%, aromatic oil. The asphalt emulsion may optionally include fromabout 0% to about 5% polymer, preferably from about 0.1% to about 1.5%polymer. In a preferred embodiment, the asphalt component is selectedfrom the group consisting of solvent extracted asphalt, oxidizedasphalt, and combinations thereof; the dispersant is Erisys® GA240; thethixotropic agent is CMC; the surfactant is selected from the groupconsisting of Redicote® E-11, Redicote® AP, Redicote® C-450, andcombinations thereof; the catalyst is selected from the group consistingof UP 1935, HCl, and combinations thereof; and the aromatic oil isdiesel fuel. In a preferred embodiment, the diesel fuel contains about65% kerosene and about 35% heavy lube oil, such as motor oil.

In another preferred embodiment of the invention, the asphalt emulsionconsists essentially of an asphalt component, a dispersant, athixotropic agent, a resin, and optionally, a polymer. In a preferredembodiment, the asphalt emulsion consists essentially of from about 1.0%to about 50%, more preferably from about 5% to about 40%, asphaltcomponent; from about 0.01% to about 1.0%, more preferably from about0.1% to about 0.5%, dispersant from about 0.01% to about 1.0%, morepreferably from about 0.1% to about 0.5%, thixotropic agent; and fromabout 1.0% to about 50%, more preferably from about 5% to about 25%,resin. The asphalt emulsion may optionally include from about 0% toabout 5% polymer, preferably from about 0.1% to about 1.5% polymer. In apreferred embodiment, the asphalt component is selected from the groupconsisting of solvent extracted asphalt, oxidized asphalt, andcombinations thereof; the dispersant is Erisys® GA240; the thixotropicagent is CMC; and the resin is urea formaldehyde.

In yet another preferred embodiment of the invention, the asphaltemulsion consists essentially of an asphalt component, a dispersant, athixotropic agent, a surfactant, a catalyst, a resin, and optionally, apolymer. In a preferred embodiment, the asphalt emulsion consistsessentially of from about 1.0% to about 50%, more preferably from about5% to about 25%, asphalt component; from about 0.01% to about 1.0%, morepreferably from about 0.1% to about 0.5%, dispersant; from about 0.01%to about 1.0%, more preferably from about 0.1% to about 0.5%,thixotropic agent; from about 0.01% to about 2.0%, more preferably fromabout 0.1% to about 1%, surfactant; from about 0.01% to about 2.0%, morepreferably from about 0.1% to about 1%, catalyst; and from about 1.0% toabout 50%, more preferably from about 5% to about 20%, resin. Theasphalt emulsion may optionally include from about 0% to about 5%polymer, preferably from about 0.1% to about 1.5% polymer. In apreferred embodiment, the asphalt component is selected from the groupconsisting of solvent extracted asphalt, oxidized asphalt, andcombinations thereof; the dispersant is Erisys® GA240; the thixotropicagent is CMC; the surfactant is selected from the group consisting ofRedicote® E-11, Redicote® AP, Redicote® C-450, and combinations thereof;the catalyst is selected from the group consisting of UP 1935, HCl, andcombinations thereof; and the resin is urea formaldehyde.

In a further preferred embodiment of the invention, the asphalt emulsionconsists essentially of an asphalt component, a surfactant, a catalyst,a resin, a cross-linking agent, a plasticizer, a wax, and optionally, apolymer. In a preferred embodiment, the asphalt emulsion consistsessentially of from about 5% to about 50%, more preferably from about10% to about 40%, asphalt component from about 0.1% to about 2.0%, morepreferably from about 0.1% to about 1.0%, surfactant; from about 0.01%to about 2.0%, more preferably from about 0.1% to about 1.0%, catalyst;from about 0.1% to about 15%, more preferably from about 0.1% to about10%, resin; from about 0.01% to about 1.0%, more preferably from about0.1% to about 0.5%, cross-linking agent; from about 0.01% to about 2.0%,more preferably from about 0.1% to about 1.0%, plasticizer; and fromabout 0.01% to about 1.0%, more preferably from about 0.1% to about0.5%, wax. The asphalt emulsion may optionally include from about 0% toabout 5% polymer, preferably from about 0.1% to about 1.5% polymer. In apreferred embodiment, the asphalt component is selected from the groupconsisting of solvent extracted asphalt, oxidized asphalt, andcombinations thereof; the surfactant is Stepanol 250A; the catalyst isUP 1935; the resin is selected from the group consisting of RE-100,Stepanol 250A, and combinations thereof; the cross-linking agent isselected from the group consisting of castor oil, Stepanol 250A, andcombinations thereof; the plasticizer is Stepanol 250A; and the wax isselected from the group consisting of CWP561, CWP461, H6 and C105.

An advantage of the present invention is that heat exchangers are notrequired during the asphalt emulsion making process. The hot asphalt,which is preferably approximately 330° F. to approximately 350° F. ismixed with components that are at or about room temperature (˜75° F.)(see Examples below). The mixture results in an emulsion whosetemperature is below the boiling point of water, i.e., below 212° F., sothat significant amounts of water that form the emulsion are not lostduring the asphalt emulsion making process. This eliminates the need foradditional equipment for cooling and thus enables cost savings.

Fibrous Mats

Asphalt roofing materials, including shingles, have traditionally andextensively been manufactured by using as a base a fibrous mat such as asheet of roofing felt or fiberglass mat, impregnating the fibrous matwith a bituminous material and coating one or both surfaces of theimpregnated mat with a weather-resistant bituminous coating material.Usually there is applied to the bituminous coating on the surfaceintended to be exposed to the weather a suitable granular material suchas slate granules or mineral surfacing. Finely divided materials such asmica flakes, talc, silica dust or the like may be made adherent to thenon-weather exposed surface of the roofing shingle to prevent stickingof the adjacent layers of the roofing material in packages.

In the present invention, a fibrous mat is provided which is made withan asphalt emulsion which allows for the preparation of the mat andbuilding materials made therefrom with improved tear resistance andtensile strength. The fibrous mats, and thus the building productsemploying them, may also be lighter in weight and cost effective.

The fibrous mat includes a fiber component and a binder component. Thefiber component is any suitable fiber. In a preferred embodiment, thefiber component comprises glass fibers. A particularly preferred fibercomponent is glass fibers supplied in bundles of glass fibers of variouslengths. In a particularly preferred embodiment, the glass fibers arefrom about 1.0″ to about 1⅜″ in length. In a more preferred embodiment,the glass fibers are 1¼″ in length, available from Owens Corning®(Toledo, Ohio). The glass fibers are preferably mixed with water, adispersant and a viscosity modifier and preferably formed into awet-laid web prior to the application of the binder component of theinvention. Suitable binder components include an asphalt-based bindermade from an asphalt emulsion of the present invention. The fibrous matsof the present invention comprise from about 50% to about 68% fibercomponent and from about 32% to about 50% binder component.

Processes for Making Fibrous Mats

In the present invention, processes are provided for manufacturingfibrous mats which employ the use of amphoteric surfactants. After theformation of a wet fiber web from a fiber dispersion, the amphotericsurfactant is applied to the wet fiber web prior to the application of abinder component to the web. The fiber mats made by the processesdescribed herein preferably include a binder component made with anasphalt emulsion which allows for the preparation of a mat and buildingmaterials made therefrom with improved tear resistance and tensilestrength and which may also be lighter in weight and cost effective.

With reference to FIG. 1, the process includes preparing a fiberdispersion by combining chopped fibers with at least water, onedispersant and a viscosity modifier. The dispersion may be prepared in aconventional head box, as shown in FIG. 1. In a further embodiment, thewet fiber web is prepared from the dispersion on a conveyor belt withthe aid of a vacuum, as shown in FIG. 1.

The fiber component is any suitable fiber useful for making fibrousmats. Preferred fiber components comprise glass fibers. A particularlypreferred fiber component is glass fibers supplied in bundles of variouslengths. In a particularly preferred embodiment, the glass fibers arefrom about 1.0″ to about 1⅜″ in length. In a more preferred embodiment,the glass fibers are 1¼″ in length, available from Owens Corning®. Theglass fibers are preferably mixed with water, a dispersant and aviscosity modifier to form a fiber dispersion. The fiber dispersion isthen formed into the wet-laid web prior to the application of the bindercomponent. The dispersant and the viscosity modifier are preferablyanionic. In a particularly preferred embodiment, Nalco® 01NM159,available from Nalco Company (Naperville, Ill.), is the dispersant andNalclear® 7768, which is an anionic acrylamide copolymer available fromNalco Company, is the viscosity modifier.

In one embodiment of the invention, the process comprises treating a wetfiber web with an amphoteric surfactant. In a preferred embodiment, theweb is treated with a solution of the amphoteric surfactant applied as aspray. The amphoteric surfactant is preferably in an amount from about0.25% to about 2.5%. In a particularly preferred embodiment, 1%amphoteric surfactant is used and is diluted in water. A preferredamphoteric surfactant of the invention is an aliphatic acid, such asChemfroth XY®, which is available from Chem-Tex Laboratories, Inc.(Concord, N.C.). Other surfactants may also be used in accordance withthe invention. Other surfactants that may be used include Chemtex®A56-25, which is a cationic amine-quat complex, and Chemtex® A-12, whichis non-ionic, both of which are also available from Chem-TexLaboratories, Inc.

In a preferred embodiment of the invention, as shown in FIG. 1, theamphoteric surfactant is applied to the wet fiber web as a spray after avacuum has been applied. Preferably, no vacuum is applied when thesurfactant is being sprayed onto the wet fiber web.

In a further preferred embodiment of the invention, after the wet web istreated with the amphoteric surfactant, a binder component is applied tothe treated wet web. In a particularly preferred embodiment, a vacuum isapplied to the treated wet web at approximately the same time as thebinder component is being applied to the treated wet web, as shown inFIG. 1.

In another preferred embodiment, the binder component is a cationicbinder component. A particularly preferred binder component is anasphalt-based binder made from an asphalt emulsion of the presentinvention.

After the binder component is applied to the treated wet fiber web, theweb may be dried in an oven at approximately 350° F. to 400° F. and thenexposed to infrared (IR) rays for cross-linking at approximately 2200°F.

Without being bound by any particular theory, Applicants believe thatthe amphoteric surfactant of the present invention, which has a neutralcharge, i.e., it includes both positive and negative charges, causes theloose welds in the wet web to open to some degree, thereby enabling atleast some of the negatively charged dispersant and viscosity modifiertherein to be released, and permitting cationic binder to enter the weldarea to enhance binding between the negatively charged glass fibers. Itis believed that some of the dispersant and viscosity modifier presentin the fiber dispersion are displaced from the welds between the fibersdue to the anionic component of the surfactant and also due to the forceof the spray. The result is a wet fiber web that is stronger and can beprocessed at a faster rate. The resultant fiber mats prepared by theprocesses of the invention have excellent tear resistance and tensilestrength. In one embodiment of the invention, the fiber mat appears moretightly packed and less susceptible to peeling than fiber mats made byconventional methods.

EXAMPLES Example 1

Table I below provides the components of an asphalt emulsion made inaccordance with one embodiment of the invention. Four parts, A, B, C andD, were prepared and then mixed together. After the four parts weremixed together, the mixture contained a total concentration of 72% ofall the components. The mixture was then diluted with water to make afinal emulsion having a final concentration of 30% of all thecomponents. This final emulsion was applied as a binder to a wet-laidglass fiber web.

TABLE I Component A B C D PDA 68% — — — HCl — 1.0% — — Redicote ® E-11 —1.0% — — CMC — 0.5% — — GA240 — — 0.5% — UP 1935 — — 0.5% — Diesel fuel— — — 0.5% Total 68% 2.5%  1% 0.5% Temperature 330-350° F. 75° F. 75° F.75° F.

Table II provides data showing the physical properties of exemplaryfibrous mats of the invention (test), which are made with the aboveembodiment of asphalt emulsion, as compared to control mats made withurea formaldehyde as the binder. Test coupon refers to exemplary fibrousmats of the invention coated with asphalt in a manner similar to theproduction of roofing shingles. Test samples 1-7, test coupon samples1-6, control samples 1 and 2, and control coupon samples 1 and 2 weremade with glass fibers that are 1¼″ in length. Where it is indicatedthat SBR was used, 2.5% Rovene® 4040 was used. Where it is indicatedthat the samples are either “hot” or “cold,” this means that the binderwas applied to the glass fibers at either approximately 165° F. (“hot”)or at room temperature (“cold”).

TABLE II Tear Tear Tear Basis Tensile Tensile Tensile Avg Min Max LOI*Weight Thickness Avg Min Max (gr) (gr) (gr) (%) (lbs./sq.) (mm) (lbs.)(lbs.) (lbs.) Test 1 (cold) 493 353 571 30 1.62 26 75 50 100 Test 2(hot) 723 642 845 29 1.57 32 57 51 76 Test 3 (cold + SBR) 795 710 867 301.59 27 88 76 100 Test 4 (cold) 721 638 772 32 1.6 26 91 86 97 Test 5(cold + SBR) 418 292 521 28 1.57 27 75 60 86 Test 6 (hot) 596 449 742 301.61 27 79 76 83 Test 7 (hot + SBR) 913 1025 800 35 1.21 24 99 80 118Control 1 314 265 380 15.8 1.59 33 76 73 79 (cold + polymer) Control 2366 300 416 14.8 1.55 26 67 58 77 (cold + polymer) Test coupon 1 904 7941123 58 Test coupon 2 989 826 1326 60 Test coupon 3 1083 979 1229 60Test coupon 4 808 707 894 58 Test coupon 5 923 774 1114 57 Test coupon 6869 758 1072 58 Control coupon 1 873 764 1020 63 Control coupon 2 808712 883 60 *LOI = Loss on Ignition

The data in Table II show that exemplary fibrous mats made in accordancewith the invention have equal to or better tear resistance and tensilestrength as compared to control conventional fibrous mats. In addition,a lighter weight fibrous mat may be used in accordance with theinvention and still achieve the required tear resistance and tensilestrength for preparing building materials employing the fibrous mats, inparticular, roofing shingles.

Example 2

Table III below provides the components of an asphalt emulsion made inaccordance with another embodiment of the invention. Three parts, A, Band C, were prepared and then mixed together. After the three parts weremixed together, the mixture contained a total concentration of 100% ofall the components. The mixture was then diluted with water to make afinal emulsion having a final concentration of 30% of all thecomponents. This final emulsion was applied as a binder to a wet-laidglass fiber web.

TABLE III Component A B C PDA 30% — — CMC — 0.5% — GA240 — 0.5% — Ureaformaldehyde — — 69% Total 30%  1% 69% Temperature 330-350° F. 75° F.75° F.

Table IV provides data showing the physical properties of exemplaryfibrous mats of the invention (test), which are made with the aboveembodiment of asphalt emulsion, as compared to control mats made with90% urea formaldehyde and 10% GL-618 acrylic (Rohm and Haas;Philadelphia, Pa.) as the binder. Test coupon refers to exemplaryfibrous mats of the invention coated with asphalt in a manner similar tothe production of roofing shingles. Test samples 1-4, test couponsamples 1-3, control samples 1 and 2, and control coupon samples 1 and 2were made with glass fibers that are 1¼″ in length. Where SBR was added,2.5% Rovene® 4040, available from Mallard Creek Polymers, was used. Theexamples that are referred to as either “hot” or “cold” indicate thetemperature of the binder when it was applied to the glass fibers. Whenthe binder was “hot” it was applied at approximately 165° F. “Cold”binder was applied at room temperature.

TABLE IV Tear Tear Tear Basis Tensile Tensile Tensile Avg Min Max LOI*Weight Thickness Avg Min Max (gr) (gr) (gr) (%) (lbs./sq.) (mm) (lbs.)(lbs.) (lbs.) Test 1 (cold + SBR) 662 536 825 30 1.6 25 90 83 94 Test 2(cold) 456 339 627 29 1.62 22 66 65 67 Test 3 (hot) 465 401 542 26 1.5621 82 67 98 Test 4 (hot + SBR) 806 700 911 40 1.2 18 76 74 79 Control 1314 265 380 15.8 1.59 33 76 73 79 (cold + polymer) Control 2 366 300 41614.8 1.55 26 67 58 77 (cold + polymer) Test coupon 1 1078 950 1248 57-60Test coupon 2 1088 801 1302 60 Test coupon 3 926 825 1020 57 Controlcoupon 1 873 764 1020 63 Control coupon 2 808 712 883 60 *LOI = Loss onIgnition

The data in Table IV show that exemplary fibrous mats made in accordancewith the invention have equal to or better tear resistance and tensilestrength as compared to the conventional fibrous mats. In addition, alighter weight fibrous mat may be used in accordance with the inventionand still achieve the required tear resistance and tensile strength forpreparing building materials employing the fibrous mats, in particular,roofing shingles.

Example 3

Table V below provides the components of an asphalt emulsion made inaccordance with yet another embodiment of the invention. Five parts, A,B, C, D and E, were prepared and then mixed together. After the fiveparts were mixed together, the mixture contained a total concentrationof 70% of all the components. The mixture was then diluted with water tomake a final emulsion having a final concentration of 30% of all thecomponents. This final emulsion was applied as a binder to a wet-laidglass fiber web.

TABLE V Component A B C D E PDA 33.5%  — — — — HCl — — — 1.0% —Redicote ® E-11 0.5% — — 1.0% — Redicote ® AP 0.5% — — — — Redicote ®C-450 0.5% — — — — CMC — — 1.0% — — GA240 — 1.0% — — — UP 1935 — — — 0.2Urea formaldehyde — — — — 30.8% Total  35%  1%  1% 2.2% 30.8%Temperature 330-350° F. 75° F. 75° F. 75° F. 75° F.

Table VI below provides data showing the physical properties of anexemplary fibrous mat of the invention (test), which are made with theabove embodiment of asphalt emulsion, as compared with control mats madewith urea formaldehyde as binder. Test coupon refers to exemplaryfibrous mats of the invention coated with asphalt in a manner similar tothe production of roofing shingles. Test sample and control sample weremade with glass fibers that are 1¼″ in length.

TABLE VI Tear Tear Tear Basis Tensile Tensile Tensile Avg Min Max LOI*Weight Thickness Avg Min Max Sample (gr) (gr) (gr) (%) (lbs./sq.) (mm)(lbs.) (lbs.) (lbs.) Test 1 548 371 809 40 1.19 24 72 lbs 70 lbs 74 lbsControl 1 314 265 360 15.8 1.6 33 67 58 77 (cold + polymer) *LOI = Losson Ignition

The data in Table VI show that exemplary fibrous mats made in accordancewith the invention have equal to or better tear resistance and tensilestrength as compared to conventional fibrous mats. In addition, alighter weight fibrous mat may be used in accordance with the inventionand still achieve the required tear resistance and tensile strength forpreparing building materials employing the fibrous mats, in particular,roofing shingles.

Example 4

Table VII below provides the components of an asphalt emulsion made inaccordance with a further embodiment of the invention. Three parts, A, Band C, were prepared and then mixed together. After the three parts weremixed together, the mixture contained a total concentration of 88% ofall the components. The mixture was then diluted with water to make afinal emulsion having a final concentration of 30% of all thecomponents. This final emulsion was applied as a binder to a wet-laidglass fiber web.

TABLE VII Component A B C PDA 80% — — RE 100 — 1.0% — CWP461 — 0.5% —Castor oil — 0.5% — Stepanol 250A — — 5% UP 1935 — — 1.0%  Total 80%  2%6% Temperature 330-350° F. 250° F. 75° F.

Table VIII below provides data showing the physical properties of anexemplary fibrous mat of the invention (test), which are made with theabove embodiment of asphalt emulsion, as compared with control mats madewith urea formaldehyde as binder. Test coupon refers to exemplaryfibrous mats of the invention coated with asphalt in a manner similar tothe production of roofing shingles. Test sample and control sample weremade with glass fibers that are 1¼″ in length.

TABLE VIII Tear Tear Tear Basis Tensile Tensile Tensile Avg Min Max LOI*Weight Thickness Avg Min Max Sample (gr) (gr) (gr) (%) (lbs./sq.) (mm)(lbs.) (lbs.) (lbs.) Test 1 579 525 627 41.7 1.22 24 98 83 116 Control 1374 265 360 15.8 1.6 33 67 58 77 (cold + polymer) *LOI = Loss onIgnition

Table IX below provides data showing the aging effects of high heat andhumidity on the tear strength of a test sample and a control samplewhich was conducted at 140° F. at 100% humidity.

TABLE IX Sample 0 hours 5 weeks Test 853 gr 742 gr Control 307 gr 217 gr

Exemplary fibrous mats made in accordance with the invention have equalto or better tear resistance and tensile strength as compared toconventional fibrous mats. In addition, a lighter weight fibrous mat maybe used in accordance with the invention and still achieve the requiredtear resistance and tensile strength for preparing building materialsemploying the fibrous mats, in particular, roofing shingles.

It should be understood that the above examples are illustrative, andthat compositions other than those described above can be used whileutilizing the principles underlying the present invention.

What is claimed is:
 1. An asphalt emulsion consisting essentially of anasphalt component, a dispersant, a thixotropic agent, a surfactant, acatalyst, and an aromatic oil, wherein the asphalt component is selectedfrom the group consisting of solvent extracted asphalt, oxidizedasphalt, and combinations thereof; wherein the dispersant is an epoxyresin dispersant; wherein the thixotropic agent is carboxymethylcellulose (CMC); wherein the surfactant is selected from the groupconsisting of a cationic surfactant and an anionic surfactant, andcombinations thereof; wherein the catalyst is hydrochloric acid (HCl);and wherein the aromatic oil is diesel fuel.
 2. An asphalt emulsionconsisting essentially of an asphalt component, a dispersant, athixotropic agent, a surfactant, a catalyst, an aromatic oil and apolymer, wherein the asphalt component is selected from the groupconsisting of solvent extracted asphalt, oxidized asphalt, andcombinations thereof; wherein the dispersant is an epoxy resindispersant; wherein the thixotropic agent is CMC; wherein the surfactantis selected from the group consisting of a cationic surfactant and ananionic surfactant, and combinations thereof; wherein the catalyst isHCl; wherein the aromatic oil is diesel fuel; and wherein the polymer isstyrene butadiene (SBR).
 3. The asphalt emulsion according to claim 1 or2, wherein the diesel fuel comprises kerosene and heavy lube oil.
 4. Anasphalt emulsion consisting essentially of an asphalt component, adispersant, a thixotropic agent, and a resin, wherein the asphaltcomponent is selected from the group consisting of solvent extractedasphalt, oxidized asphalt, and combinations thereof; wherein thedispersant is an epoxy resin dispersant; wherein the thixotropic agentis CMC; and wherein the resin is urea formaldehyde.
 5. An asphaltemulsion consisting essentially of an asphalt component, a dispersant, athixotropic agent, a resin, and a polymer, wherein the asphalt componentis selected from the group consisting of solvent extracted asphalt,oxidized asphalt, and combinations thereof; wherein the dispersant is anepoxy resin dispersant; wherein the thixotropic agent is CMC; whereinthe resin is urea formaldehyde, and wherein the polymer is SBR.
 6. Anasphalt emulsion consisting essentially of an asphalt component, adispersant, a thixotropic agent, a surfactant, a catalyst, and a resin,wherein the asphalt component is selected from the group consisting ofsolvent extracted asphalt, oxidized asphalt, and combinations thereof;wherein the dispersant is an epoxy resin dispersant; wherein thethixotropic agent is CMC; wherein the surfactant is selected from thegroup consisting of a cationic surfactant and an anionic surfactant, andcombinations thereof; wherein the catalyst is HCl; and wherein the resincomprises urea formaldehyde.
 7. An asphalt emulsion consistingessentially of an asphalt component, a dispersant, a thixotropic agent,a surfactant, a catalyst, a resin and a polymer, wherein the asphaltcomponent is selected from the group consisting of solvent extractedasphalt, oxidized asphalt, and combinations thereof; wherein thedispersant is an epoxy resin dispersant; wherein the thixotropic agentis CMC; wherein the surfactant is selected from the group consisting ofa cationic surfactant and an anionic surfactant, and combinationsthereof; wherein the catalyst is HCl; wherein the resin comprises ureaformaldehyde; and wherein the polymer is SBR.